code: def test_contour_interiors():
      # produces a polygon with multiple holes:
      nx, ny = 10, 10
      numlev = 2
      lons, lats = np.meshgrid(
          np.linspace(-50, 50, nx), np.linspace(-45, 45, ny)
      )
      data = np.sin(np.sqrt(lons**2 + lats**2))
      fig = plt.figure()
  
      ax = fig.add_subplot(2, 2, 1, projection=ccrs.PlateCarree())
      ax.set_global()
      ax.contourf(
          lons, lats, data, numlev, transform=ccrs.PlateCarree()
      )
      ax.coastlines()
  
      ax = fig.add_subplot(2, 2, 2, projection=ccrs.Robinson())
      ax.set_global()
      ax.contourf(
          lons, lats, data, numlev, transform=ccrs.PlateCarree()
      )
      ax.coastlines()
  
      # produces singular polygons (zero area polygons)
  
      numlev = 2
      x, y = np.meshgrid(
          np.arange(-5.5, 5.5, 0.25), np.arange(-5.5, 5.5, 0.25)
      )
      dim = x.shape[0]
      data = np.sin(np.sqrt(x**2 + y**2))
      lats = np.arange(dim) + 30
      lons = np.arange(dim) - 20
  
      ax = fig.add_subplot(2, 2, 3, projection=ccrs.PlateCarree())
      ax.set_global()
      ax.contourf(
          lons, lats, data, numlev, transform=ccrs.PlateCarree()
      )
      ax.coastlines()
  
      ax = fig.add_subplot(2, 2, 4, projection=ccrs.Robinson())
      ax.set_global()
      ax.contourf(
          lons, lats, data, numlev, transform=ccrs.PlateCarree()
      )
      ax.coastlines()
  
      return fig
  
file_path: cartopy/lib/cartopy/tests/mpl/test_shapely_to_mpl.py
imports: from matplotlib.collections import PatchCollection
  import matplotlib.patches
  from matplotlib.path import Path
  import matplotlib.pyplot
  import numpy
  import pytest
  import shapely.geometry
  import cartopy.crs
  import cartopy.mpl.patch
label_desc: Use image node_id 2 for calling a global function with example usage: test_contour_interiors() and returns: fig